Organic peroxy ester anti-seizure agent



United States Patent 3,296,139 ORGANIC PEROXY ESTER ANTI-SEIZURE AGENTArthur M. Shapiro, Philadelphia, Pa., assignor to the United States ofAmerica as represented by the Secretary of the Army No Drawing. FiledMar. 4, 1965, Ser. No. 437,323

- 5 Claims. (Cl. 252-57) The invention described herein may bemanufactured and used by or for the Government for governmental purposeswithout the payment to me of any royalty thereon.

This invention relates to improved lubricants containing as a majorlubricating component oil of mineral origin. In particular, theinvention relates to lubricating compositions of this type havingimproved anti-seizure and anti-wear characteristics.

A particular property required by many mineral base lubricants usedtoday is an ability to prevent seizure and scoring of relatively movingmetallic surfaces operating under extremely high pressures per unitarea, in many cases considerably in excess of 10,000 psi. Pressures onthis order have long been encountered in the machine industry and inmetal machining operations which undergo extremely high pressure loads.Consequently, for 'effective lubrication, lubricants capable ofwithstanding pressures appreciably higher than those at which ordinarymineral base oil lubricant films will rupture have been required.

It is therefore a principal object of the invention to provide acompounded lubricating product of mineral base oil possessing goodanti-seizure and anti-wear characteristics of a high order as thoseencountered in high speed cutting of metals and in other diverse machineoperations where high pressures are present.

It is another object of the invention to provide a lubricant havingimproved anti-seizure and anti-wear properties, said lubricantcomprising a major proportion of an oil of mineral origin having anorganic peroxy ester blended therewith.

Other objects and features of the invention will become apparent as theinvention is more fully hereinafter disclosed.

In accordance with these objects it has been discovered that minoradditions of an organic peroxy ester to mineral based oils arecharacterized by good anti-seizure and antiwear properties. Morespecifically, I have found that t-butyl perbenzoate is capable ofimparting these desirable properties to mineral base oils.

Mineral oil SAE only is presented in the table following. It is to beunderstood however that the invention is not to be considered as beinglimited to this specific viscosity as it will be apparent to thoseskilled in the art that a wide variety of viscosities of mineral oilsmay be employed in formulating the lubricant contemplated herein.

The lubricity agent of my present invention is available commercially,0.5 through 3.0 weight percentages of tbutyl perbenzoate, having anempirical formula of C H O a molecular weight of 194.2 and a structuralformula of was intimately blended with varying SAE mineral oils and thensubjected to anti-seizure and anti-wear evaluation tests. These testswere conducted on conventional laboratory equipment and will not bedescribed, their operations being well known to those skilled in theart. For example, anti-wear data were obtained on the Shell "ice 4-ballwear tester while anti-seizure data were determined using the well knownFalex extreme pressure tester. Description of the Shell 4-ball testermay be found in an article by G. D. Boerlage, Engineering, vol. 136(1933), p. 46 et seq. The Falex extreme pressure tester is described inLubrication Engineering, September 1946, V. A. Ryan.

The tabulated comparative data following illustrates the extremepressure or anti-seizure and anti-wear effectiveness of the presentinvention when incorporated in a mineral base oil such as SAE 10.

Wt. Shell 4-Ba11 Falex Extreme Additive Percent Wear Scar Pressure J awAdditive Diameter Load at (mm) Failure (lbs) The wear tests wereconducted on standard 52100 steel whereas the extreme pressure testswere conducted with blocks of C1144 steel and a pin of SAE 8640 steel.In addition to the property of being able to withstand high anti-seizureloads and wear there are other factors which must be considered inevaluating a lubricant. Among the most important is the tendency of thelubricant to corrode the containers in which it is stored and the metalswith which it comes in contact during use. The above tabulated data showmy t-butyl perbenzoate to impart excellent anti-seizure and anti-wearproperties to steel machining operations. Commercial cutting oilsnormally contain phosphorous, chlorine and sulfur type additives, thelatter two being the most corrosive.

It should be apparent therefor that the lubricant of my presentinvention, being devoid of these harmful elements will not tend tocorrode the metals as greatly as commercial cutting oils.

All values presented in the table are averages of five differentmeasurements. Maximum variance among the five values was confined towithin a 10% range. Although 0.5 to 3.0 weight percentages of thelubricity additive of my invention is presented only, it should beunderstood that intermediate additions were found equally satisfactory,that is, between 0.5 and 3.0 weight percentages.

From the data hereinabove set forth, it will become evident that thelubricity additive of the present invention, when confined within theprescribed range, improves both anti-seizure and anti-Wearcharacteristics of the mineral base oil. Further, its corrosivetendencies are considerably lower than the presently used commercialcutting oils. Amounts of my respective lubricity additive below about0.5 weight percent do not produce suflicient advantageous effects torender the composite oil lubricant adequate for anti-seizure andanti-wear use. Similarly, if the additive is incorporated with themineral oil in quantities greater than about 3 weight percent, thecomposite lubricant shows little further improvement in the level ofthese properties and, in several instances, a slight decrease in levelsresults.

I claim:

1. A lubricant composition having good anti-seizure, anti-wear andanti-corrosive properties suitable for use in various machine cuttingoperations, said lubricant composition consisting essentially of about0.5 to 3.0 weight percent of t-butyl perbenzoate and the balance beingan oil of mineral origin.

4 2. A lubricant according to claim 1 wherein said t-butyl ReferencesCited by the Examiner perbenzoate is present in an amount of about0.5weight UNITED STATES A E percent. I

3. A lubricant according to claim 1 wherein said t-butyl 17665O1 6/1930Buerk 44-47 perbenzoate is present in an amount of about 1.0 weight 5OTHER F RENCES percent. Sato et a1.: Chemical Abstracts, page7941,.vo1ume 4. A lubricant according to claim 1 wherein said t- 5. 3(1959), Effect of Peroxides on the Rust Preventing butyl perbenzoate ispresent in an amount of about 2.0 Properties of Oils." weight percent. 7

5. A lubricant according to claim 1 wherein said t-butyl 1O DANIEL WYMANPnmary Examme" perbenzoate is present in an amount of 3.0 weightpercent. W. H. CANNON, Assistant Examiner.

1. A LUBRICANT COMPOSITION HAVING GOOD ANIT-SEIZURE, ANTI-WEAR ANDANTI-CORROSIVE PROPERTIES SUITABLE FOR USE IN VARIOUS MACHINE CUTTINGOPERATIONS, SAID LUBRICANT COMPOSITION CONSISTING ESSENTIALLY OF ABOUT0.5 TO 3.0 WEIGHT PERCENT OF T-BUTYL PERBENZOATE AND THE BALANCE BEINGAN OIL OF MINERAL ORIGIN.